Tattooing is a widespread and increasingly popular practice of decorating an individual's skin via the injection of colored pigment dispersed in tattoo ink into the skin into small holes formed therein by a tattoo device or needle. Millions of individuals around the world have at least one permanent tattoo, and with the current popularity of so-called “body art”, more and more young men and women of an average age of 18 years are acquiring tattoos. Depending upon the area of the body being tattooed, the artwork may or may not be easily concealed by clothing, and tattoos acquired in youth may become embarrassing in later life and create an impediment to employment opportunities and overall social acceptance. Accordingly, a substantial commercial market for tattoo removal has developed.
Tattoo removal is a more difficult, painful and, quite possibly, more expensive process than the initial application of the tattoo itself which entails injecting pigments of various colors into the dermis. The dermis is the skin layer which lies immediately beneath the approximately 1 mm thick epidermis—the dead, outer external surface skin layer. In newly applied tattoos, the ink pigments tend to aggregate near the upper dermis close to the epidermis, and early techniques for tattoo removal used abrasives to abrade away the epidermis above the tattoo pigment to reach and abrade away the pigment itself. Clearly, this technique is painful and may expose a subject to infection and permanent scarring. Moreover, over time, the tattoo pigments may become encapsulated in fibroblasts and migrate deeper into the dermis, making older tattoos more difficult to remove by abrasion.
With the discovery of the laser, a non-abrasive technique became available for tattoo removal. Experiments with the application of laser energy to permanent ink tattoos were performed in the late 1960's using continuous wave argon and later carbon dioxide lasers, which, in effect, burned off the tattoo. The undesirable but foreseeable side effect of these painful processes was permanent scarring in the former location of the tattoo.
In the late 1980's the development of pulsed or Q-switched lasers provided a commercially practical technique for the treatment of various dermatological pigmentation issues, including the removal of tattoos. Q-switching is a technique for obtaining high energy nanosecond pulses of laser energy from solid-state lasers, and by selecting the laser energy wavelength or color so that the tattoo ink pigment absorbs the laser energy more readily than the surrounding skin, the tattoo may be removed by thermal photo ablation. At sufficient energy levels, the laser pulses cause the thousands of particles of tattoo pigment in the skin to heat up and photo ablate or fragment into smaller pieces as a result of the inherent thermal shock waves generated by the laser energy. The pigment fragments are normally no longer colored and are then diffusibly removed by normal body processes.
Since tattoo pigments cover a wide range of colors, no single laser wavelength is suitable for tattoo removal by photo ablation. The selective ablation of ink pigments depends upon four factors:                The color of the laser energy must penetrate sufficiently deep into the skin to reach the tattoo pigment.        The color of the laser energy must be selected such that it is more highly absorbed by the tattoo pigment than by the surrounding skin tissue-accordingly, different tattoo pigments require different laser colors.        Laser energy pulse duration must be very short so that the tattoo pigment is heated to fragmentary temperature before its heat can dissipate to the surrounding tissue so as to prevent scarring.        Sufficient energy must be delivered during each laser pulse to heat the pigment to fragmentation. Otherwise, no removal will occur.        
The application of laser energy to and the resulting heating of the skin and the formation of highly localized thermal shock waves in the dermis are the principal sources of trauma in the laser treatment and removal of tattoos. Typically, more than one treatment is necessary to remove the entire tattoo, and the procedures are painful, expensive and may result in permanent scarring and/or pigment color variations after the healing process is completed.
Various attempts have been made to develop a less painful and less costly method of removing or at least concealing permanent ink tattoos. One such method disclosed in U.S. Pat. No. 5,833,649 issued to Atef on Nov. 10, 1998, for Method and Kit for Disguising Tattoos, teaches a method of concealing tattoos on an individual which includes the steps of adding various coloring pigments to tattooing ink until a color which matches the person's skin color is attained. The colored ink is brushed over the brushed over the tattoo to conceal it. It may be made permanent by injecting the skin-colored ink into the tattoo. However, this method does not affect permanent removal of the tattoo and must be repeated on a regular basis to maintain the concealment.
Malak discloses Methods and Devices for Plasmon Enhanced Medical and Cosmetic Procedures in U.S. Patent Application Publication No. US 2005/0203495 published Sep. 15, 2005, which suggests that a method of tissue ablation using nanosecond pulses of laser energy which exhibit strong electromagnetic fields may be used in conjunction with magnetic nano bodies injected into the dermis in close proximity to the tattoo ink pigment particles. The laser energy pulses interact with the nano particles to release surface plasmon resonance (SPR) illumination to effectively photodecompose the pigment. Nonetheless, Malak's approach is at this stage theoretical in concept and involves an undisclosed number of painful injections into a tattoo to be effective.
More recently, Smits et al. in U.S. Patent Application Publication No. 2012/0215209, for Tattoo Removal and Other Dermatological Treatments Using Multi-Photon Processing, published Aug. 23, 2012, disclose a system and method for removing a portion of a tattoo using a relatively low energy, multi-photon intense pulse of light to ablate the tattoo ink in a highly localized area. While the Sits et al. process claims to minimize surrounding tissue damage, it does not eliminate it, and the process still requires multiple passes to effectively remove a tattoo.
In view of the foregoing, a tattoo removal system and method is needed which provides for effective, painless, scar-free tattoo removal which may be accomplished economically in a single session without the need for multiple treatments.